Jump to content

Recommended Posts

Posted
low_STSCI-H-p1228a-k-1340x520.png

With large swaths of oceans, rivers that snake for hundreds of miles, and behemoth glaciers near the north and south poles, Earth doesn't seem to have a water shortage. And yet, less than one percent of our planet's mass is locked up in water, and even that may have been delivered by comets and asteroids after Earth's initial formation. Astronomers have been puzzled by Earth's water deficiency. The standard model explaining how the solar system formed from a protoplanetary disk, a swirling disk of gas and dust surrounding our Sun, billions of years ago, suggests that our planet should be a water world. Earth should have formed from icy material in a zone around the Sun where temperatures were cold enough for ices to condense out of the disk. Therefore, Earth should have formed from material rich in water. So why is our planet comparatively dry?

A new analysis of the common accretion-disk model explaining how planets form in a debris disk around our Sun uncovered a possible reason for Earth's comparative dryness. In this study astrophysicists Rebecca Martin and Mario Livio found that our planet formed from rocky debris in a dry, hotter region, inside of the so-called "snow line." The snow line in our solar system currently lies in the middle of the asteroid belt, a reservoir of rubble between Mars and Jupiter; beyond this point, the Sun's light is too weak to melt the icy debris left over from the protoplanetary disk. Previous accretion-disk models suggested that the snow line was much closer to the Sun 4.5 billion years ago, when Earth formed.

View the full article

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Similar Topics

    • By NASA
      1 min read
      Preparations for Next Moonwalk Simulations Underway (and Underwater)
      On April 16, 2025, the Earth Science Division at NASA’s Ames Research Center in Silicon Valley held an Earth Science Showcase to share its work with the center and their families. As part of this event, kids were invited to share something they like about the Earth. These are their masterpieces.

      Sora U. Age 9. “Wildlife”

      Sora U. Age 9. “Wildlife” Wesley P. Age 2.5. “Pale Blue”

      Wesley P. Age 2.5. “Pale Blue” Kira U. Age 5. “Hawaii”

      Kira U. Age 5. “Hawaii” Anonymous. “eARTh”

      Anonymous. “eARTh” Brooks P. Age 8mo. “Squiggles”

      Brooks P. Age 8mo. “Squiggles” About the Author
      Milan Loiacono
      Science Communication SpecialistMilan Loiacono is a science communication specialist for the Earth Science Division at NASA Ames Research Center.
      Share
      Details
      Last Updated Apr 25, 2025 Related Terms
      Earth Science Ames Research Center Ames Research Center's Science Directorate Earth Science Division Keep Exploring Discover More Topics From NASA
      Missions
      Humans in Space
      Climate Change
      Solar System
      View the full article
    • By European Space Agency
      Image: Copernicus Sentinel-1 captured this radar image over French Guiana – home to Europe’s Spaceport in Kourou, where ESA’s Biomass mission is being prepared for liftoff on 29 April onboard a Vega-C rocket. View the full article
    • By European Space Agency
      Video: 00:02:22 ESA’s state-of-the-art Biomass  mission has been designed to shed new light on the health and dynamics of the world’s forests, revealing how they are changing over time and, critically, enhancing our understanding of their role in the global carbon cycle. It is the first satellite to carry a fully polarimetric P-band synthetic aperture radar for interferometric imaging. Thanks to the long wavelength of P-band, around 70 cm, the radar signal can slice through the forest canopy and whole forest layer to measure the ‘biomass’, meaning the woody trunks, branches and stems, which is where trees store most of their carbon.
      View the full article
    • By NASA
      NASA The Sun’s glint beams off a partly cloudy Atlantic Ocean just after sunrise as the International Space Station orbited 263 miles above on March 5, 2025. The space station serves as a unique platform for observing Earth with both hands-on and automated equipment. Station crew members have produced hundreds of thousands of images, recording phenomena such as storms in real time, observing natural events such as volcanic eruptions as they happen, and providing input to ground personnel for programming automated Earth-sensing systems.
      NASA has been observing Earth from space for more than 60 years, with cutting-edge scientific technology that can revolutionize our understanding of our home planet and provide benefits to all humanity.
      Image credit: NASA
      View the full article
    • By NASA
      Seeing Earth as Only NASA Can
  • Check out these Videos

×
×
  • Create New...